How to block access to iframe page?

Question

Nginx

there is an iframe page on the site.ru site, which is designed to insert the player on other sites, how to block access to this page on the site.ru site, and allow it if the page is inserted into other sites?

Answer 1

if ( $http_referer ~ site.ru ){
return 403;
}

Answer 2

You have already answered the question by asking it correctly.
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xsef.ru/6c300461